©Wellcome Library, London

Mendel is pictured standing second from right in this photograph taken at the Augustinian monastery in Brno (then in Moravia but now the Czech Republic) where he carried out breeding experiments with the common garden pea (Pisum sativum). He showed that certain elements of inheritance such as tallness were dominant whilst others were recessive. If offspring inherit 2 dominant elements or one dominant and one recessive, the dominant trait will be observed. Only when 2 recessive elements are present will the recessive trait appear. Characters inherited in this fashion are called ‘Mendelian'.

Source: Hugo Iltis. Life of Mendel. Allen & Unwin, London (1932).